A superb blog in the NYTimes Opinionator column by Steven Strogatz on the Golden Ratio, phi and its reverence in the world of design.
If unfamiliar with the golden ratio, "google it" and one of the 6 million results should present an elementary understanding. Needless to say, it has significant application in landscape design to even very small, urban garden design.
*Image of Parthenon from http://zlatnirez.springnote.com/pages/5692507.xhtml